<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
   <script>
     function radio(){
       var val=$('input[name="radio"]:checked').val();
       alert("当前选中的radio控件的值"+val)
     }
   </script>
</head>
<body>
<script src="https://cdn.staticfile.org/jquery/2.2.4/jquery.min.js"></script>
<input type="radio" name="radio" value="1" onclick="radio()" />
<label>a</label>

<input type="radio" name="radio" value="2" onclick="radio()" /><label>b</label>

<input type="radio" name="radio" value="3" onclick="radio()" /><label>c</label>

<input type="radio" name="radio" value="4" onclick="radio()" /><label>d</label>
</body>
</html>
